Expansion joint filler



June 11, 1946. E. M. JENKINS ETAL 2,401,936.

EXPANS ION JOINT FILLER Filed m- 29, 1945 INVENTOR I [01/41/420 2%. (Am/47mm 04/40 1057361959.

WWQKZAAL ATTORNEY Patented June 11, 1946 UNITED STATES PATENT OFFICE EXPANSION JOINT FILLER; I Edward M. Jenkins and David Loetscher, Somerville, N. 1., assignors to Johns-Manville COM- ration, New York, N. Y., a corporation of New York Application n 29, 194:. Serial No.,488,992

'1 Claims.

' 1 Our invention relates sion joint filler, for use in connection with structures of various types which are subject to expansion and contraction, and particularly to structures such as concrete roadways. Heretoi'ore it has been conventional in the constructo an improved expantion of concrete roadways and the like to divide filler strips of a felted fibrous material and has for its primary 'object the provision of an improved strip of this type, which will completely fill the expansion joint spaces under all service conditions.

As will be understood, concrete is not usually laid in the coldest weather and also is in a more or less wet and expanded condition at the time the filler strips are inserted. Consequently the spaces will, due to initial concrete shrinkage and the later normal contraction of the slabs, increase in width after insertion of the strips. Where the ordinary fibrous strips are employed a gap is left between the strip and the slab which destroys the continuity of surface and also permits the filler strip to work out of the joint as well as the entry of dirt and soil. carrying water into the space. Another object of the invention is the provision of a preformed fibrous filler strip adapted to expand beyond its initial thickness to insure a tight fit in the joint under all conditions.

Another object of the invention is the provision of a filler strip of the character referred to. composed of felted wood or like relatively inexpensive, fibrous materials. Afurther object of the invention is the provision of. a filler strip which is resistant to de 1 further object of the invention is the pro-- vision of a filler strip composed of felted fibrous v 2 ness and which'in the absence of moisture will retain such reduced thickness.

A still further object of-the invention is the provision of a method of making filler strips of the type referred to above.

Our invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description which is to follow and to the accompanying drawing. in which;

Fig. 1 is a perspective view. with broken away for clearness of illustration, of an expansion joint 'filler strip in accordance with the invention; and,

Fig. 2 is a sectional view, taken transversely of the expansion joint through a roadway pavementor the like, illustrating the filler strip in operative position. a

Referring to the drawing, there is showna filler strip ill for roadways and similar structures, the strip comprising a compressed felt of ligneous vegetable fibers l2, particularly wood fibers, and an interspersed binding and preserving agent ll.

Fibers II.- which may be of any suitable ligneous wood, are of a special character. More particularly, they are long. relatively coarse, curly, resilient fibers produced preferably by the known Asplund process. involving mechanical defiberization or grinding of wood chips, softened by being subjected to a steaming treatment in which V the steam penetrates into the pores of the wood. Fibers formed by this processemploying .a relatively coarse setting of the "Asplund" defiberizer. have the curly, resilient characteristics required for the instant invention. It will be understood that the-invention is not limited to the use of fibers produced by the Asplund process. as they may be obtained in any way that will give them similar characteristics with respect to curliness and resiliency.

The felted strip of fibers containing the intermingled binder. when ready-for use as an expansion joint filler strip (see. Fig. 1) is substantially compressed, as will hereafter be more fully explained, so that it maybe easily fitted into the expansion space between concrete paving slabs I! or the like. (See Fig. 2.) At the same time the strip, due to the type of fibers employed ""and the offabrication. whenso posi- 7 materials. which, during fabrication is compressed to athickness less than its normal thick;

tioned and subjected to moi weathering iniiuences, tathe action of rain and other moisture, is capable pf'increasing its thickness by Vs to ,5 or more-.. In consequence. further contraction of th concrste 'slabsafter insertion of the filler strip will not produce unfilled pore and of expanding substantially when wetted, saidslab comprising an intertelted mass of coarse 6 Asplund fibers and an interspersed binder and formed by subjecting a layer of said-fibers and binder to heat and pressure to reduce the thickv ness of the layer to substantially lessthan its uncompressed thickness and thoroughly drying said layer while maintained under. compression.

EDWARD M. JENKINS. DAVID LOETSCHZER. 

